President Barack Obama and his progressives can grab control of the nation’s constitution if he gets to appoint a Supreme Court replacement for Antonin Scalia, says Ed Whelan, a former law clerk for Scalia.

“If President Obama has another appointee to this Court, we’re going to have an entrenchment of the Left on constitutional issues for the next generations, or so and a great deal will be lost on a whole range of issues in a way that might not ever be recoverable,” he told Breitbart News Sunday host Alex Marlow, on Sirius XMPatriot channel 125.

Whelan, who is now President of the Ethics and Public Policy Center and writes at National Review Online’s Bench Memos, joined Breitbart News Sunday to discuss Scalia’s recent passing from a heart attack at age 79, leaving the court with three conservatives, four liberals and one swing-vote.

Senate Republicans would be grossly irresponsible to allow President Obama, in the last months of his presidency, to cement a liberal majority that will wreak havoc on the Constitution. Let the people decide in November who will select the next justice.

Whelan called Scalia a “gregarious, joyful person” who “loved vigorous argument and struggled to get cases right,” while noting his “wonderful laugh” and calling him “challenging and intimidating, a great mentor and great judge.”

Politically, Whelan said conservatives not only lost a great Justice, and are at risk of losing the Supreme Court and the Constitution given the timing of his passing.

Whelan praised Scalia, saying he “blazed a trail that many others have followed in, his textualist approach (which) is dominant now.” even though some Justices often veer from it to get the result they want.

He credited Scalia and also Judge Robert Bork for reviving “the Constitutionalist or originalist approach to the Constitution in the 1980s — that the words meant what they were understood to mean when they were adopted.”

Whelan said Scalia “transformed” the Court in terms of “how it generally approaches statutory and Constitutional issues” as a rival to living Constitutionalists.

The entire Breitbart news Sunday interview with Ed Whelan can be heard below.